Field of Invention
The invention relates to a display apparatus and a light-emitting module and a light-guiding plate thereof.
Related Art
Recently, because the manufacturing process and material of light-emitting diode (LED) are improved unceasingly, the light-emitting efficiency of LED is enhanced enormously. Different from the fluorescent lamp or compact fluorescent lamp, LED has some wonderful characteristics, such as less power consumption, long lifespan, high safety, short response time and small size, thus gradually applied to a lighting apparatus, a lighting case or a lighting module. The lighting apparatus is such as an indoor or outdoor lamp, a flashlight, a headlight or taillight of a vehicle, or other kind of the lighting apparatus. The lighting module can be applied as a backlight module of a display apparatus or otherwise.
FIG. 1A is a schematic exploded diagram of a conventional display apparatus 1, and FIG. 1B is a side view of the display apparatus 1.
The display apparatus 1 includes a display panel 11 and a light-emitting module 12. The light-emitting module 12 is a backlight module of the display apparatus 1, emitting the light L through the display panel 11 for displaying images.
The light-emitting module 12 is disposed on a side of the display panel 11, and can include two lateral light sources 121, a light-guiding plate 122 and a plurality of light-guiding elements 123. The lateral light sources 121 are instanced as two LED light bars. They are disposed on two opposite sides of the light-guiding plate 122, respectively, and emit the light L entering the light-guiding plate 122 through a light input surface I of the light-guiding plate 122. Each of the light-guiding elements 123 is white ink in a form of an oblique strip, and is disposed on a bottom surface B1 of the light-guiding plate 122 by coating. The light is guided to the center portion of the light-guiding plate 122 from the lateral sides of the light-guiding plate 122 by the total reflection. The light-guiding elements 123 can interfere with the total reflection of the light so that the light can be emitted through a light output surface O of the light-guiding plate 122 and towards the display panel 11 for displaying images.
However, when the light L is outputted through the light output surface O of the light-guiding plate 122 and towards the display panel 11, the light output on the light output surface O is formed into an alternate form (alternating arrangement) of bright and dark oblique strips. For example, the odd strips are bright and the even strips are dark. By adding the influence of the light-shielding layer (i.e. the opaque black matrix, not shown) disposed in the display panel 11 in the form of strips, the light outputted through the display panel 11 will generate interference fringes (only one interference fringe is shown in the area A of FIG. 1C while the rest are not shown) due to the diffraction, shown by the area A in FIG. 1C (in which the straight strips M are caused by the light L passing through the light-shielding layer, and the oblique strips N are caused by the light on the light output surface O in an alternate form (alternating arrangement) of bright and dark oblique strips). The interference fringes are the so-called Moiré phenomenon, decreasing the display quality of the display apparatus 1.
Therefore, it is an important subject to provide a light-emitting module and a display apparatus that can change the light output form and interfere with interference fringes to improve the display quality.